Internal-combustion engine with rotary constant volume combustion chamber



Sept. 30, 1952 J. F. KEYS INTERNAL-COMBUSTION ENGINE WITH ROTARY vCONSTANT VOLUME COMBUSTION CHAMBER 4 Sheets-Sheet' 1 Filed une; 7'. 1945Sept. 30, 1952 J. F. KEYS INTERNAL-COMBUSTION ENGINE WITH ROTARYCONSTANT VOLUME coMBusTIoN CHAMBER Filed Dec. 7,"1945 -4 sveetsheet 5vBY A* I f Jf I l TTORNEK.

xjg' o u y INVEJQTORV'.

Sept.- 30, 1952' F. KEYS TI INTERNAL-COMBUS CONSTANT VOLUME Filed DSG.7' 1945 ON ENGINE WITH ROTARY,

coMBUsTIoN Chmn/nalgavr A' Sheetssheet 4 Patented Sept. 30, 1952 OFFICENTERNAL-COMBUSTION ENGINE WITH ROTARY CONSTANT VOLUME COM- BUSTIONCHAMBER Joseph F. Keys, Wichita,

.Application December 7, 1945, Serial'No. 633,299

This vinvention .relates .to improvements in a 'power unit and refersmore particularly. to .a unit employing a compressor and `gas propelledlprime mover yon .a single shaft timed or synchronized with a :constantvvolume combustion .chamber operated `under relatively high pressure. A

The -unit seeks to obtain the advantages of ldecreased temperatureresulting from the introduction -of moisture to .the air vsupplied tothe .compressor and regulates .the amount of moisture .in .the airsupplied to the combustion chamber by a separator interposed :betweenthe compressor .and combustion chamber.

An .object then is to ,provide a power unit in which .the compressor.,yseparator yand gas .propelled prime mover are mounted on a continuousvsha'ftoperating in conjunction witha combustion gas source geared to.and timed with the compressor shaft to supply high `pressure gas to theprlme mover. l l

Another Objectis .to provide a unit wherein moisture is added to the airsupplied to the compressor and .separated .from the airprior to itsintroduction to the combustion chamber.

Another object is to provide .a supplementary .bypass connectionv.between .the compressor discharge .and combustion chamber forregulating the amount of moistureand dry air .supplied .to the latter.

A further Objectis to provide an improved type of compressordesign of.the helical gear type utilizing a plurality .of Agears .arranged aboutthe periphery of a central rotor and meshing with an internal .gear onthe inside of the `interior of 'the compressor housing to increase thecapacity and improve efficiency. of "the compressor. v

Another object i/sjto ,provide a power unit employing a constant volumecombustion chamber interposed between the compressor and prime mover towhich is continuously introduced air and fuel to form a combustiblemixture which is ignited inthe combustion Vvchamber andv is dischargedto the vga's propelled prime mover.

other and further objects will appear from the following description.

In 'the accompanying drawings which form a part of the specication andare to be read in conjunction therewith .and in which like `referencenumerals indicate like ,parts in the various views,

Fig. 1 is a diagrammatic side elevational view of -a .power unitembodyingthe invention.

2 is an enlarged elevational view of the .14y claims. (o1. ca -39.35)

.-nition :means diagrammatically .shown at combustion .chamber yshown inFig. :1 ywith -parte broken away and parts in section,

y .'Fig. v3 is a View taken along the .line 3--3y in Fig. .2 in thedrectionof the arrows,

Fig. :4 is a view taken along the line 44 in Fig. `2 in the direction ofthe arrows,

Fig. 5 is `an enlarged 'sectional view ofthe compressor.,

Fig. V6 .is a view .taken along the line -6`-6 in Fig. 5 in the.direction .of .the arrows,

Fig. 6a .is a 'View taken along the .line 1{a-i5 in Fig. 5 in thedirection ofthe arrows,

Fig. yl is a View taken along the line --i vin Fig. 5 in the directionofthe arrows,

Fig. 8 is a sectional view of the "centriftugal -air- :moistureseparator taken along the line-8 8 in Fig. 9,

-separator and moist air from the .compressor are supplied to thecombustion chamber,

Fig. V1.3 -is .an enlarged velevation of the cornbustion chamber shownin Fig. l2 with parts in section,

Fig. .14.is a view taken .along the .line l 4-14 .in Fig.. 13 and Fig.15 is a view taken along the line -i5-l5 in Fig. 13.

Referring to the `drawings and .briefly describing .the voperation of.the vpower vunit shown yin Fig. `1 air-is supplied to thecompressor I0.through the ,inlet opening lila, as indicated by `the arrows. vAt theinlet moisture-is lsupplied through a ,plurality `of pipes -II, the.injection of the moisture being through .mist-producing .spray .jets todisperse the moisture luniformlythrough the yair. On being discharged.from the compressor the vmoisture .laden air is passed `through a,separator i2 where the water is removed from the air :by centrifugalseparation. The water isl drawn off `from the .separator through pipe i3anddry air through pipe 114, the latter to be introducedto the.combustion chamber. I5. a In the combustion chamber the `dried air issupplied with fuel through pipe I6 and the combustible mixture .ignitedby a .het -spot or electrical ig- Il.. Within the -combustionchamber isa radially par titioned rotor mounted upon the shaft IS driven from thecompressor shaft i9 through meshing gears 20 and 2l.

After ignition in combustion chamber I5. which is of the constant volumetype, the ignited gases are discharged at decreasing pressures through aplurality of ducts 22 and introduced to a gas propelled primemoverdiagrammatically shown at 23 as a conventional multi-stage gas turbine.Duets 22 are spaced lengthwise of the turbine to communicate with thesuccessive stages or pressure zones therein, the zone of maximumpressure being at the small end.

The compressor I, water separator I2 and prime mover 23 are mounted upona continuous shaft I9. Compressor shaft I9 and shaft I8 which drive therotor in the combustion chamber are supported at one end by the standard24 and at their opposite ends by suitable bearing supports not shown.rIhe exhaust gases are discharged from the prime mover through pipe 25.

A modified type of power unit is shown diagrammatically in Fig. 12. Theprincipal difference between the unit shown in Figs. 1 and 12 is theprovision in the latter for transferring moist air from the compressordischarge directly to the combustion chamber through a supplementary orauxiliary pipe 26. In the modified type unit the dry air from theseparator and fuel are combined in a carbureting device 2l and thecombustible mixture supplied to the combustion chamber in ar manner toassure ignition and without objectionable blending with the moist airsupplied through pipe 28 as Will he hereinafter explained.

To facilitate an understanding of the units their elements will bedescribed in the order that they occur in the drawings.

'Combustion chamber-Figs. 2, 3 and 4 Interposed between the waterseparator and prime mover is a constant volume combustion chamberdesignated in Figs. 1 and l2 by the numeral I5. This chamber consists ofa cylindrical housing Ia closed at its ends by plates I5b and I5c. Thehousing is supported on a suitable base or standard not shown. The shaftI8 extends centrally through the housing and on the shaft within thecombustion chamber is mounted a rotor 2B divided by radial partitions28a. The inlet plate 95h of the chamber has an air inlet port I-I and afuel supply jet I6. Closure plate I5c of the chamber is equipped with anoutlet manifold 22a to which pipes 22 are connected. Mounted in plateI5c adjacent the low pressure outlet port 22o is an electricallycontrolled hotspot or plug Il for igniting fuel air mixture introducedthrough pipes It and Ill. The operating cycle, in so far as thecombustion chamber is concerned, may be briefly described as follows:

Dry air from the separator is introduced through pipe I4 and fuelthrough pipe I6. The rotor within the combustion chamber is revolv ingwith the shaft I8 in the direction shown by the arrow in Fig. 3. The airinlet is located opposite the low pressure port 22o and serves as ascavenging agent besides introducing air for combustion. The fuel isintroduced t0 the cells as they rotate to a position opposite thehot-spot plug. In other words, the introduction of the air takes placewhen a cell is in registration with the inlet port I4 and outlet 22o andfuel injection when the cell registers substantially with the igniter.With ignition and combustion the temperature of the charge increasedwhile it is 4 maintained at a constant volume. Consequently, thepressure of the gaseous mixture within the cell is greatly increased.Each successive cell receiving a combustible charge is successivelyignited and rotated to a discharge position where the gases areexhausted through the manifold into pipes 22 to drive the prime mover.It will be noted that all radial partitions 28a of the rotor are taperedas shown at 28h in Figs. 2 and 3 and certain of the manifold partitionedas shown at 22d in Figs. 2 and 4 to close the exhaust ports while a cellis passing from one pressure duct of the manifold to an adjacent duct oflower pressure. The details of the 'fuel injector and the electricallycontrolled hot spot for igniting the gases are all of minor consequencein so far as this invention is concerned, it being essential only thatthe fuel injection and ignition is efficiently accomplished.

The construction of the combustion chamber has been described and itwould new appear to be in order to describe in somewhat more detail theoperation.

Referring first to the combustion chamber shown in Fig. 1, as a cell 28hof the rotor revolves to a position in registration with the intakemanifold a supply of dried air from the separator is introduced throughpipe ill. As this air enters it exhausts from the opposite side of thecell remaining power gas which ilows out through a low pressure duct ofthe exhaust manifold. The cell charged with dried air is then rotated toa position in registration with the fuel jet and ignition hot spot orplug. At this position fuel is injected and the mixture ignited. At thetime of ignition and through the combustion period this cell of therotor is sealed from both intake and exhaust and remains at constantvolume. Further rotation uncovers the `high pressure section of theexhaust manifold through which a portion of the high pressure power gasis exhausted into the conduit which directs the gas to a high pressurenozzle of the prime mover. With further rotation the cell which is nowexhausting the confined power gas moves across the lower pressure ductsof the manifold discharging its gas into the manifold ducts until itreaches the final stage which is the beginning of a new cycle. In thefinal low pressure stage the cell again registers both with the intakemanifold and with the low pressure duct of the exhaust manifold. Itshould be noted that the exhaust sides of the radial cell walls and theintake side of the dividing Walls of the exhaust manifold have baffles,as shown in Figs. 3 and 4, which effectively function as valves as thecells are rotated by the manifold closing the cells to the exhaustpassages ywhile passing from one pressure duct of the manifold to alower pressure duct and providing an open passageway when a cell is inregistration with only one exhaust duct. This valve action is, however,effective principally in the intermediate or narrow ducts of the exhaustmanifold since the high and low pressure sections are of double thewidth and the flow through these particular ducts is continuous. In theintermediate narrow sections the flow is intermittent but at such arapid rate that the pulsations produce a substantially continuous flowof power gas through the ducts. Thus, it will be seen that the power gasgenerated in each cell of the rotor is exhausted through the successiveducts of the exhaust manifold until it reaches the low pressure exhaustduct vcompressor-Figs. `5, 6, 6a and 7 The compressor, designated asawhole in Figs. land 12 .by the .numeral HJ, consists of an .outercylindrical casing vlila supported on suitable standards not shown. Atthe discharge end Aflange -lb of the casing is bolted to ange V12b ofthe separator casing 12a. Through a portion of its length within thecompressor hous- -ing or casing a is an internal helical gear, as shownin cross section "at lc. The teeth of this internal gear mesh with theteeth of a plurality of helical gears 29. Gears 29 are carried by shafts3U which bear in a frame or Lspider 3l keyed to shaft 18. Also i'ixedlymounted upon and rotating Awith shaft i9 'is a rotor 32. The `shape of4the `rotor is 'best indicated 'in Figs. 6 `and 6a. It will `-be notedfrom these two figures that the ends of the rotor arms movein a circledefined by the crests of the internal helical gear. The spaces betweenthe arms are substantially semicylindrical to accommodate the pluralityof rotating helical gears 29. noted that the arms of the rotor taperlongitudinally from the inlet end of the -compressor 'toward thedischarge end providing -a larger amount of space between gears 29 andthe arms of the rotor at the inlet than lat the outlet, as shown inFigs. 6 and 6a. In other words, the arms of the rotor do not fit asclosely Aabout the .helical gears 29 at the inlet end as they do at vthedischarge end providing an increased amount of space for theintroduction of air `which gradually diminishes to a minimum at lthedischarge ends of theA gears. Rotating with the spider 3| and helicalgears 29 and mounted at the discharge end of the gears is -a plate 33.The plate 'is notched at four locations two of which are shown in Fig.'7 and designated by the numeral 33a. The width of these openings isdecreased when the discharge pressure of the compressor is increased andenlarged when the discharge pressure is decreased. Discharge Iplate 33,therefore, serves as a closure plate at the discharge end of the helicalgears and rotor thus preventing the previously compressed air from'backing up into the pressure passagewa1 of the compressor.

Shaft I9 bears in rotor bearings 3d which are carried by radial supports35. Rotation of the helical gears A29 would result from rotation of thespider or frame 3i upon which they are mounted and the fact that theirteeth mesh with the teeth of the internal helical gear.

It should yalso be There is, however, provided separate driving gearsadapted to reduce frictional contact between gears 29 and the internalgear of the compressor housing. These driving gears comprise a largeinternal gear 3B cut 'in a boss formed in the housing l2@ whose 'teethmesh with pinions 31 mounted on shafts 3B at the discharge end ofthecompressor.

In operation th-e compressor functions as follows: Air is introducedthrough inlet maand enters the spaces surrounding the teeth .of thehelical gears 29 .and between these teeth and the rotor arms as well asthe .spaces between the teeth of the internal .gear and the extremitiesof the rotor arms. Since the teeth of the helical gears mesh with theinternal gear a relatively tight compression chamber is created in the-compressor between the inlet and discharge. With rotation of the shaftthe rotor and spider .sup-

porting the peripheral `gears .surrounding the .rotor l.also `revolve.IIihe xair charge `advances ialongthe gears `with their rotation to be'dis- .charged atta maximum pressure .through notches .33a in Kthedischarge plate. y .air receives va charge :of .highly dispersed ewaterAmist '.or :other coolant .from the atomizingjets vIl the temperature`of ...the air is raised much .less during its compression.

Returning to themanner in which pressure von =the .airy-is increased inthe compressor, 'the .rotation -of helical gears .-29 .about -the axis:of `the shaft .and rotor :and rotation of these gears upon :their own4axis fduc to engagement with the internal gear and driving gears 3E andSly :compresses -air .Supplied through the inlet lila. .As the helicalteeth lof l'gears f2s engage the teeth yof the ,internal gear alongadiagonal :li-ne of vcontact the meshing -of the teeth progresses asfthe gears from .the inlet .en d of the compressor .move toward thedischarge end reducing the volume .of the fair trapped between the'toothed .spaces -as .the contacting surfaces advance.

Externalfgear type .rotary .screw compressors .are well adapted to highspeed -operation existent when l-the compressor .is mountedl upont-heshaft of a high speed prime mover suc-h' as sa turbine as shown.However, for a given tooth depth and pitch circle diameter the .externalgear type compressor provides approximately one-third the number ofhelical teeth and toothed spaces as 'the vinternal gear type `of likedimensions. This ldifference is due to the .different speeds .at

'which the engaging toothed surfaces :move'in` the two types ofconstruction. .In .theexternal typethe .outer extremities of .the 'teethare always internal gear within the compressor housing provides .asystem wherein the outer tooth extremities of the smaller gears movingfaster than the ypitch circles of said gears engage the root surfaces ofthe internal gear. .Also the outer tooth .extremities of the internalgear advance along the'root surfaces of the engaging smaller gears at arate relatively Vslower than the common pitch circle speed. This closerapproximation of the same speed for the engaging tooth surfaces oftherespective gears permits a much narrower tooth and toothed spaces. Thevery substantial increase in the .number of teeth is most important forhigh compression. In a screw gear `compressor operating without actualcontact of engaging surfaces the .maximum pressure is .proportional .tothe .number of pressure zones provided between the compressor intake andoutlet. rIhese .zones are limited to the number of teeth and toothedspaces under compression between the inlet .and outlet passageways.

Another advantage of the compressor utilizing ,an .internal gear is thatit lends itself to a closer approach to isothermal compression throughVits ability to carry a heavy Charge of moisture combined with the airwithout danger of moisture separation and failure of the mechanismoccasioned by lling of the clearance spaces with liquid. .By Voffering a-closer approach `to isothermal compression the power required .tooperate the compressor i-s less than in single stage .adiabaticcompression. Savings in total power Since the intake necessary tooperate the compressor are of the order of 18% to 35% depending on' thefinal pressure at the discharge from the compressor. This is especiallyimportant in a gas turbine unit where the mass of air compressed isoften as much as four times the mass needed for complete combustion ofthe fuel charge. A compressor of this type into which a water mist ischarged lends itself admirably to the use of rubber surfaced gears toform a positive seal and` provide higher pressures without heavy leakagelosses. The water mist in such operation oifersY an exceedinglyeffective lubricant between the rubber covered surfaces; also, if buthalf of the' working surfaces vare rubber lm bonded the water mist is aneifective lubricant between the rubber and metal. It is contemplatedthat the large internal gear in the casing and the cavities between thearms of the rotor could be rubberized while the peripheral helical gears23 wouldhave metal surfaces. This design offers a compressor which wouldbe eiciently lubricated with the water mist or humidity present in theair being compressed. A further advantage of this type of compressor isthe absence of valves and the necessity for maintaining end clearanceswhich impair volumetric eiiiciency.

Moisture separator-Figs. 8, 9, cmd f1 The housing i211 of thewaterseparator is bolted to the discharge end of the compressor. Thehousing itself is in two parts centrally flanged and bolted, as shown incross section inv Fig. 8. At the discharge end of the separator `ispacking gland 38 which seals the housing about shaft i9. Mounted uponthe shaft within the housing are concentric shells 39 and lid, the innershell having substantially the diameter of the shaft at its ends andtapering to an extreme diameter centrally of the housing. The outershell 4G also has its minimum diameter at its extremities and itsmaximum diameter at its central portion. Longitudinal radial varies ilare located in the annular space between shells 39 and til. The vanesare pitched slightly, as shown in Fig. 9, to facilitate the flow of airthrough the separator. Shells Si' and et are mounted on shaft i9 androtate with the shaft. Centrally of the outer shell are a plurality ofapertures lila through which separated moisture is discharged as theshells rotate. Water discharged frorn apertures Ma passes from theseparator housing through a drain hole i2 into a trap t3 below theseparator. In the trap is a float control 44 which regulates a dischargevalve l i5 in the liquid drawoif line i3.

Moisture laden air discharged from the coniprcssor passes through thepartitioned annular space between rotating shells 3Q and dil. Whilepassing through these ducts the heavier particles of moisture areprojected by centrifugal force to the inner surface of the outer shellwhere they accumulate and drain off through holes fida. This moisturedrains into the bottom of the separator housing and passes out throughaperture 42 to the water trap 43 from which it is discharged by floatregulated valve d5.

The dehumidiiied air passing through the ducts between the shells formedby partitions il follows the course shown by the arrows and isdischarged from the separator through pipe ill through which it isdirected to the combustion chamber.

In so far as the separator is concerned centriiugal separation of fluidsof different weights is recognized to be old practice, but in theseparator employed in the instant power unit separation is effectedwithout seriously reducing the rate of iiow of the air between thecompressor and combustion chamber. A further advantage of the separatoris its large capacity at high speed.

Modified type combustion chamber-Figs 13, 14 and 15 The construction ofthe combustion chamber used inthis modied type of power unit shown inFig. 12 is generally similar kto that shown in Figs. 2, 3, and 4. Thechamber housing 15a is closed at its ends by an inlet plate 15b and anoutlet plate I 5c. Through the housing extends shaft i3 upon which ismounted rotor 23 separated into cells or explosion chambers by radialpartitions 28a. Connected into the inlet plate of the chamber is amanifold il centrally divided into two separate ducts dla' and Mb, asindicated in Fig. 14. Into one of the ducts lla of the manifold isconnected pipe 43 through which passes the combustible mixture of fueland air from carburetor 27. To the other duct Alb is connected pipe 26through which moisture laden air discharged from the compressor ispassed to the combustion chamber. Pipe Id, which carries dry air fromthe separator to the carburetor, is provided with a valve Ilia, andlikewise pipe 25 is equipped with a valve Se for regulating the flow ofmoisture laden air to the combustion chamber. The electricallycontrolled hot spot cr plug I7 in this modification is mounted on theinlet plate. Connected into the outlet plate i 5c is the dischargemanifold 22a similarly partitioned, as in Fig. 2.

In this modied type combustion chamber rotor 2B, as before, revolveswith the shaft it. When one of the combustion cells 28h registers withthe inlet manifold d?, a charge of the combustible mixture is introducedthrough ducts dla and a charge of moisture laden air through duct ll'ib,the relative proportions of which are controlled as desired by valvesida and 26a. The sequence in which the separate charges of combustiblemixture and moisture laden air are introduced are arranged to render thecombustible mixture more readily available to ignition by plug il. Uponignition the pressure of the gases within the cell immediately rises andis discharged upon rotation of the rotor when the cell registers withthe discharge openings in the exhaust manifold as described. Theexpanded gases are directed as before through pipes 22 to the primemover.

The operation of the combustion chamber used in the power unit of Fig.12 and detailed in Figs. 13, 14 and l5, in general, is similar to thatjust described. In this chamber, however, instead of introducing sucientexcess air into each cell to reduce combustion temperature to thatdesired a charge of humidiiied air is introduced to the cells to reducethe temperature. The mechanism for accomplishing this is shown in Fig.12 where a stream of the humidied air is taken from the unit ahead ofthe separator and is conducted to the intake manifold through a separateconduit. By division of the'intake manifold into separate ducts themoisture laden air is charged to each cell prior to the introduction ofthe combustible mixture. At the time of injecting the combustiblemixture the gas in the cell is again ignited and the cycle proceeds asbefore. In the operation of this type combustion chamber a carburetingdevice is employed in- @ergere stead of a fuel jet. Also thel'iot'sptorignition means is located in the intake plate to ignite the combustiblemixture which is` the l'as't charg'evto enter the combustion cell. `Alsothe-intakeopem ing must have such dimensions asto give the-enfteringcharge a ow speed in excessfofthe speed of flame propagation toavoid aareback' through the intake opening.V Y I The rotors Within theAcombustion chain-bers provide a revolving series of individualcombustion cells wherein fuel charges are lsi'ilcfzessively ignited andcombustiorsubstantially completed at constant volumebefore?u'nl'.:o'verir'igz ports that lead to the prine`x`rioverl- Bye'plbyinga series of contiguous exhaust' pcrtsfl conducting the power gasfrom the combus hamb 'rto the prime mover a range ofi pressu fromlthehighestv pressure to substantially compessor'presfsure are employed.Atv'th sariie'ti'r'l this ar` propriate pressure iones tliel` prime'-mover in a steady flow and at pressures suit'able` for the respectivepressure stages of the prime mover. If a jet propulsion prime mover is"usedi one or more of the exhaust conduits from theeoi'ribusg-v tionchamber could drivey the'- turbol'corripres'sor While the balance'woul-dbe conduotedtothejet propulsion nozzles?.-

Alterna-tive operation' An operation not" shown" but. firiteiplatedwould be one in which the pdweriuriit'tilized air from the compressorcharged with` a' predetermined amount of moisture and without separa'-tion of any of the moisture' on discharge' from the compressor. Thisoperation would4 dispense with the water separator' entirely butgund'rsuch conditions the moisture added to the" airv must be closelycontrolled within limits which would provide the desiredcharacteristicsY to the combustible mixture and'would riot u'n'dulydampen the expansive force of the ga'ses'' when ignited in thecombustion chamber.

In this third type of operationywhere the separator is eliminated andthe control of moisture in the air is governed by" the introductioh ofwater to the compressor' inleti regulation ofthe air and fuel to eachce'l'l'of theicornbustion hmber would bev controlled as" in the' unit4sho ri in Fig. 1. The amount of excess"a'ir andv degree to which the airwas; liui'hidied w ,y d" in this type ofv operationbe'theimp'ortant"factors for controlling the combustiorrat'a propertemperature. In all adaptations described manual control of the fuelinlet'. would governptl'e` control of the speed of the 'pririe n'over.Ifit is desired to operate' the" prri'ie mover at` constant speed aconventional governing device could be used to control the fuelrationing to the combustion chamber.

In all types of operation a starting motor, not shown, would be providedto rotate shaft I9 until the elements of the units begin to function.Ro-

tation of the main compressor shaft charges moisture laden compressedair to the separator.

In the separator, according to the type unit which is beingoperated, allor a portion of the moisture is extracted from the air. From theseparator the air passes to the combustion chamber where it is ignitedand combustion takes place while the gases are maintained at a constantvolume. The power gas is then discharged at this increased pressurethrough pipes 22 to the prime mover. In so far as the combustion chamberis concerned important gains in the to the'rcombustion of `fuel possiblewith this type'v Compre ranged about' tnejper ne @vergif efficiency ofthe amemcienoeseffeddri ,n are possi-ble with the.y .type-,Of Savings'are substantial-1d h ewigen wir n 'o`inbi 1st ion` isat constantpressfure ash tional in most g's; mij units'l Itis generally rec nizeripag .Costgni i011., greater' than tl'iosef` employi-rrg'v roi-ii theforegoing it invention' is one: endsarid objects' with (other stricter@nous, ice vn gas popelledprimerrove y A. l y ti'iiuus' shaft,- n'iaiisYfor' introducing/moisture ito the air sppiied'to' 'the' "eipr'sbri a;@existant volume combustion device having a fuel supply'. interposedbetween the compressor and prime mover, a conduit from the compressor tothe separator for the passage of high pressure moist air, a conduit fromthe separator to the combustion device for the passage of high pressuredry air and a plurality of pipe connections` between the combustiondevice and prime mover for the passage of power gas, the gas being atdifferent pressures in the respective ones of said last pipeconnections.

5. A power unit of the character described, comprising a multi-stage gasturbine having a plurality of gas intake ducts connected respectively tosaid stages, the other end of said ducts connecting to a common housing,a rotor in said housing connected to and driven by said turbine.

@manages au" n er ases and aciayoaa 1 I 8 cavity in the rotor definingwith the interior of the housing an. enclosed chamber adapted toregister with said ducts successively as the rotor turns. means forintroducing a combustible mixture into said cavity when it is out ofregister with said ducts, and means for igniting the mixture. 'GA powerunit of the character described, comprising `a multi-stage gas turbinehaving a plurality of gas intake ducts connected respectively to saidstages, the other end of said ducts connecting to a common housing, arotor in said -lioiising connected to and driven by said turbine, aplurality of cavities in the rotor each defining with the interior ofthe housing an enclosed chamber adapted to register with said ductssuccessively as the rotor turns, means for introducing a combustiblemixture into each cavity in -turn as it reaches a predetermined positionout of register with the ducts, and means for igniting the mixture ineach cavity in turn as said cavity 'reaches another predeterminedposition.

7. A power unit of the character described comprising a multi-stage gasturbine having a plurality of gas intake ducts connected respectively tosaid stages, a combustion chamber, means for introducing a combustiblemixture into said chamber and igniting same, said chamber having valveapparatus connected to anddriven by. said turbine for connecting thechamber to the diierent ones of said ducts successively during thecombustion cycle of the mixture.

8. A power unit of the character described comprising a multi-stage gasturbine having a plurality of gas intake ducts connected respectivelytosaid stages, a plurality of combustion chambers, means for introducing acombustible mixture into said chambers in cyclic succession and ignitingthe mixture in each chamber, and cyclically-operated valve apparatus forconnecting the chambers tothe ducts in turn, whereby each duct alwayshas connected thereto a combustion chamber wherein the mixture hasreached a predetermined point in the combustion cycle.

9. A power unit of the character described comprising a gas propelledprime: mover having a i plurality of gas intakeducts, an air compressorconnected toand driven by the prime mover, 'means for introducingmoisture into the -air supplied to said compressor, Ia moistureseparator connected to the compressors exhaust to remove `the `moisturefrom the compressed air, a combustion chamber connected to the separatorto receive the dried air therefrom, means for introducing fuel into theair in said chamber and igniting the resultant combustible mixture, saidchamber having valve apparatus driven by said prime mover for connectingthe chamber to the different ones of said ducts successively during thecombustion cycle of the mixture.

10. A power unit as in claim 9 wherein said moisture separator is1 facentrifugal separator driven by said prime mover.

l1. A power unit as in claim 9 having a supplementary connection betweenthe compressor and the combustion chamber whereby moist air dischargedfrom the compressor may bypass the separator. y

12. A power unit of the. character described comprising a compressor, aseparator and a gas propelled prime mover mounted on a shaft, means forintroducing moisture to the air supplied to the compressor, a constantvolume combustion chamber, a radially partitioned rotor mounted on aseparate shaft geared to the compressor shaft and rotating within thecombustion chamber, said rotor forming a plurality of pockets with thecombustion chamber, ignition and fuel means operative with thecombustion chamber, combustion chamber inlet and discharge portsconnecting with said pockets, the inlet port connected with theseparator and the discharge port with the prime mover, and asupplementary connection between the compressor and combustion chamberwhereby moist air discharged from the compressor may bypass theseparator.

13. A power unit as in claim 12 including controis for regulating therelative proportions of moisture denuded air and moist air supplied tothe combu-stion chamber.

14.v A power unit asin claim 9 including a supplementary connectionbetween the compressor and the combustion chamber and controls forregulating the relative proportions of moisture denuded air and moistair supplied to the combustion chamber. A

JOSEPH F. KEYS.

REFERENCES orrsn The following references are-of record in the ile ofthis patent: f

` STATES PATENTS Great Britain Nov. 29, 1917

